Indicating device for use in connection with grinding tools



March 24-, 1936. v FGLSCHE 2,035,119

INDICATING DEVICE FOR USE IN CONNECTION WITH GRINDING TOOLS Filed July2, 1954 3 SheetsSheet 1 March 24, 1936. V 'j c 2,035,119

INDICATING DEVICE FOR USE IN CONNECTION WITH GRINDING TOOLS Filed July2, 1954 3 Sheets-Sheet 2 Wm. M

March 24, 1936. v FOLSCHE 2,035,119

INDICATING DEVICE FOR USE IN CONNECTION WITH GRINDING TOOLS Filed July2, 195 3 Sheets-Sheet s Patented Mar. 24, 1936 i UNITED STATESINDICATING DEVICE FOR USE IN CONNEC- TION WITH GRINDING TOOLS ViktorFiilsche, Velten, near Berlin, Germany Application July 2, 1934, SerialNo. 733,391 In Germany July 4, 1933 Claims. (Cl. 51165) This inventionrelates to an indicating device for use in connection with grindingtools in-.

ground on both sides of the wheel by correspondingly disposed grindingvdevices. Machines adapted to be used for the plane Working of blanksconsisting of all sorts of materials, for example ceramic plates,stovetiles, and the like, and employed ona large scale require carefulsupervision of the groups of grinding means arranged on both sides ofthe feed gear, each of which may comprise a combination of a pluralityof successive grinding wheels for roughing andfinishing, because thesegrinding means are subjected to a relatively large wear owing to thenecessary speeds and output.

If the grinding wheels are worn down beyond a certain limit, accurateworking, particularly with respect tomeasurements, is no longerpossible. In numerous fields of application, e. g., those mentionedabove, not only wear but also too much advance for one or the otherwheel during the original adjustment would have a detrimental effect, asthe glazing of ceramic products might crack off and the entire work bedestroyed. I r The control of the accuracy of the working methoddepended hitherto chiefly on the attention of the operator who hadcontinually to adjust the various grinding wheels by hand according towear, which was inconvenient, required a relatively large amount of workand lacked absolute reliability.

The invention eliminates these troubles by providing a device forvisibly indicating the working operation as Well as enabling the wear ofgrinding wheels in machines of the type described to be determined, sothat the operator, by glancing at a scale or other indicating device,always knows exactly whether Wear is still within permissible limits orthe wheels have to be adjusted one way or other. Furthermore, accordingto the invention, the grinding wheels are adjusted from a central placeof control, and not singly, and means are provided for automaticallystopping the feed gear in case of errors in operation, service troublesof the grinding motors or excessive wear of the grinding wheels.

By way of example, one form of the invention as applied to stove tilesis illustrated in the accompanying drawings, in which Figure 1 is apartial cross section of a grinding device showing somewhatdiagrammaticallythe control de- 5 vice according to the invention; Fig.2, a side view thereof; and Fig. 3, a plan of the device showing thecentrally controlled operating members for the adjustment of theindividual grinding means, only one control device being shown in Figs.2 and 3.

Referring to the drawings, a is the feed gear carrying at its outercircumference the fixing means b for holding the work consisting in theexample shown of the tiles 0. The feed gear a further carries on bothsides the rims 01 concentrically disposed with the axis of the gear a ata slight distance from the outer circumference thereof. The rims d havea wavelike surface and as many wavecrests e and wave troughs f as thereare fixing means b on the circumference of the gear a, so that eachfixing means is provided with a wave crest and trough, or, in otherWords, wave crests or troughs will always be found at those points ofthe rims d which correspond, in radial direction, to the fixing means.

During the rotation of the feed gear a the rims d disposed on bothsidesthereof, i. e., their wave crests and troughs, are engaged byfeelers g preferably fitted with the rolls g, each feeler g beingsecured to a lever h rotatable about the axis 1'. The lever h, isactuated by a spiral spring is which is firmly arranged and has thetendency to act on the free arm of the lever so as to press the feeler gdisposed on the other lever arm onto 5 the surface of the rims d. Inthis Way, the lever' h is controlled by the wave crests and troughs ofthe rims d and carries out a slow oscillating motion. Through a bore orforklike portion of the lever 71., as shown in the free arm thereof, 40

extends a shaft p which can be reciprocated in a fixed guide q on theframe of the device and which carries at its front end asecond feeler 1whose feeling surface is coated with a protective layer of highlyresisting material, preferably 5 widia steel. Widia steel is a materialwell known in Germany,'and comprises an alloy of Wolfram-carbidecontaining a small amount of cobalt, it being a product of Krupp, Essen.This feeler l or itsshaft p, for instance by means of a driving pin 1'disposed on the shaft 10 or of a disc, etc., is alternately withdrawnfrom the feed gear a and released again by the motion of the lever h inone direction or the other. When released, it is pressed upon the feedgear a by the action of a spring s disposed in the guide q. The courseof these motions of the shaft 1) and thus of the feeler l is controlledby the feeler g rolling over the control faces e and f on the feed geara in such a Way that the measuring feeler I will be released for freemotion towards the feed gear a when a piece of Work passes the measuringdevice andfor placing'itself for a short time upon the side thereof tobe worked. As soon as the entire work has passed the measuring point, orshortly before, other control faces begin to act and the measuringfeeler is lifted off again.

In the embodiment shown the working position of the measuring feelerinvolves a wave crest of the control surfaces, which turns the lever hclockwise about the pin 2', so"that the driving pin' 1" is out ofengagement. When the feeler 9 passes into a wave trough, the lever hwill act again upon the pin 1- and withdraw the measuring feeler fromthe feed gear against the action of the spring 5.

Both feelers may of course be arranged on the same side of the lever, inwhich case the association of the wave crests and troughs will bereversed, or the measuring feeler may be connected with the lever.

' Owing to the control described, the feeler I will not begin orcontinue to touch the side of the tile before the work is opposite it,as otherwise the passing edge of the work would destroy it.

In the manner described the degree of motion of the feeler l towards thefeed gear a, which can be easily transmitted to a scale or the like,will indicate the degree of working and thus of wear, or the adjustmentof the grinding wheels, which can then be read off. For example, thetransmission of the measuring results is effected by causing the feelerl or its shaft p to act by the rods t upon a second lever arranged sothat it can move' directly over a scale a or actuate the indicatingdevice in some other way. This scale is preferably cylindrical tofacilitate reading, and the scales of each working device associatedwith each grinding motor are preferably united to form a centralcontrol.

In the indicating device shown the lever 111. will deflect towards theleft if the grinding wheels are adjusted too far with respect to thefeed gear and thus too thick a chip is taken off. On the other hand,ifthe wear of the grinding wheels has progressed too far and machiningthus become unsatisfactory, the lever 'm. will deflect towards the righton the scale shown when the blank passes the feeler Z. It is thereforepossible to fix in a simple may a standard point or interval on thescale within which the deflections ofthe indicating instrument must takeplace, so that the grinding means concerned may be adjusted as soon asthese deflections are too great in either direction. As in otherindicating instruments, the scale may show different colors or possessspecial marks for the range of permissible deflection, or signals, suchas bells, may be provided for sounding an alarm when the permissibletolerances are exceeded.

The various grinding devices, each of which is associated with ameasuring device of the type described, can thus be adjusted to accuratecutting ranging for instance from 5 mm. for roughing to 1 mm. forpreparatory and 0.5 mm. for final finishing.

It is advisable to provide incombination with, or in addition to, thecontrol devices other devices for stopping the feed gear in case ofoverloading of a grinding wheel, e. g., if a wrong adjustment has beenmade by mistake, so as to prevent destruction of the grinding devices.

It is further preferable to connect the stopping devices with thegrinding means, that is, one stopping device with one grinding means, insuch a way that the stopping devices will act when the grinding meansare worn down to a certain deall individual adjustments and adjustaccordingly from his central control position on one side of the machinethe motors y by actuating the hand wheels a (Fig. 3) which, by meansof'bevel gears 22, control the drives w by chains or the like.

The application of the control device according to the invention is ofcourse not limited to the grinding device for tiles, ceramic plates,etc. shown, but the device, in combination with correspondingly alteredworking and fixing means, may be used also for controlling the workingof other materials.

The invention is, further, not restricted to the constructionalembodiment shown, but may be applied in many ways by changing theconstruction without departing from the spirit of it.

I claim:-

1. An indicating device for use in connection with grinding wheelshandling fiat-surfaced or flat-edged blanks fed to the grinding wheelsby a gear provided with fixing means for the blanks, comprising, incombination, a feeler for measuring the working degree while the blankis passing the measuring station, means for withdrawing the feeler fromthe path of the blank, means for returning the feeler to the path of theblank, an indicating instrument for recording the degree of working, andmeans for connecting said feeler with said indicating instrument.

2. An indicating device for use in connection with grinding wheelshandling flat-surfaced or flat-edged blanks fed to the wheels by a gearprovided with fixing means for the blanks, comprising, in combination, afeeler for measuring the working degree while the blank is passing themeasuring station, means for withdrawing the feeler from the path of theblank, means for returning the feeler to the path of the blank, anindicating instrument for recording the degree of working, means forconnecting said feeler with said indicating instrument, a second feelerfor controlling the first feeler, said second feeler cooperating with awavelike rim on the feed gear, said rim having crests and troughs ascontrol surfaces, each of said surfaces being associated with acorresponding blank fixing means.

3. A device according to claim 2, comprising a reciprocating shaft forthe measuring feeler, a fixed guide for said shaft in the frame of thedevice, 7 a lever carrying the control feeler, said lever withdrawingthe measuring feeler from the feed gear when the feeler is inintermediate position between the fixing means, and a spring forpressing the feeler upon the side of the blank when the blank and thefeeler are opposite one another.

4. A device according to. claim 2, comprising a reciprocating shaft forthe measuring feeler, a

fixed guide for said shaft in the frame of the device, a lever carryingthe control feeler, said shaft passing through a bore in said lever,driving means on said shaft for engaging with said lever andalternately, on rotation of said lever, withdrawing the measuring feelerfrom the feed gear and releasing it again when the feeler faces a blank,and a spring for pressing 'the released feeler against the side of theblank.

5. A device according to claim 2, comprising a reciprocating shaft forthe measuring feeler, a fixed guide for said shaft in the frame of thedevice, a lever carrying the control feeler, said lever withdrawing themeasuring feeler from the feed gear when the measuring feeler is inintermediate position between the fixing means, a spring for pressingthe feeler against the side of the blank when the blank and the feelerare opposite one another, a second lever adapted to actuate directly orindirectly the indicating instrument, and means connecting the shaftwith said second lever.

VIKTOR FOLSCHE.

